Polymorphisms in DNA-Repair Genes in a Cohort of Prostate Cancer Patients from Different Areas in Spain: Heterogeneity between Populations as a Confounding Factor in Association Studies.

BACKGROUND Differences in the distribution of genotypes between individuals of the same ethnicity are an important confounder factor commonly undervalued in typical association studies conducted in radiogenomics. OBJECTIVE To evaluate the genotypic distribution of SNPs in a wide set of Spanish prostate cancer patients for determine the homogeneity of the population and to disclose potential bias. DESIGN SETTING AND PARTICIPANTS A total of 601 prostate cancer patients from Andalusia, Basque Country, Canary and Catalonia were genotyped for 10 SNPs located in 6 different genes associated to DNA repair: XRCC1 (rs25487, rs25489, rs1799782), ERCC2 (rs13181), ERCC1 (rs11615), LIG4 (rs1805388, rs1805386), ATM (rs17503908, rs1800057) and P53 (rs1042522). The SNP genotyping was made in a Biotrove OpenArray® NT Cycler. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Comparisons of genotypic and allelic frequencies among populations, as well as haplotype analyses were determined using the web-based environment SNPator. Principal component analysis was made using the SnpMatrix and XSnpMatrix classes and methods implemented as an R package. Non-supervised hierarchical cluster of SNP was made using MultiExperiment Viewer. RESULTS AND LIMITATIONS We observed that genotype distribution of 4 out 10 SNPs was statistically different among the studied populations, showing the greatest differences between Andalusia and Catalonia. These observations were confirmed in cluster analysis, principal component analysis and in the differential distribution of haplotypes among the populations. Because tumor characteristics have not been taken into account, it is possible that some polymorphisms may influence tumor characteristics in the same way that it may pose a risk factor for other disease characteristics. CONCLUSION Differences in distribution of genotypes within different populations of the same ethnicity could be an important confounding factor responsible for the lack of validation of SNPs associated with radiation-induced toxicity, especially when extensive meta-analysis with subjects from different countries are carried out.

Transaortic Fallot repair in a grown-up patient: advantages in a situs inversus setting.

We present the case studies of two adult patients with tetralogy of Fallot who were scheduled for surgery. After addressing the right ventricular outflow tract obstruction, the aorta was opened and the ventricular septal defect was approached in a straightforward manner as it was located just under the overriding aortic valve. The second patient presented with was a situs inversus, dextroapex Fallot. In this setting, the aortic approach simplified the repair expeditiously. After 2 years, both patients are in New York Heart Association class I, with no residual ventricular septal defect, no aortic regurgitation, and complete relief of right ventricular outflow tract obstruction.

How Can Nanotechnology Help to Repair the Body? Advances in Cardiac, Skin, Bone, Cartilage and Nerve Tissue Regeneration

Nanotechnologists have become involved in regenerative medicine via creation of biomaterials and nanostructures with potential clinical implications. Their aim is to develop systems that can mimic, reinforce or even create in vivo tissue repair strategies. In fact, in the last decade, important advances in the field of tissue engineering, cell therapy and cell delivery have already been achieved. In this review, we will delve into the latest research advances and discuss whether cell and/or tissue repair devices are a possibility. Focusing on the application of nanotechnology in tissue engineering research, this review highlights recent advances in the application of nano-engineered scaffolds designed to replace or restore the followed tissues: (i) skin; (ii) cartilage; (iii) bone; (iv) nerve; and (v) cardiac.

Surgical excision with left atrial reconstruction of a primary functioning retrocardiac paraganglioma.

About 2% of all paragangliomas are located in the chest, and a few have been described to be found in the heart. Primary cardiac paragangliomas are extremely uncommon tumors and surgical experience with this neoplasm is limited. Treatment strategies described in the literature have included simple excision, excision with reconstruction, autotransplantation after excision of the tumor and even orthotopic cardiac transplantation, depending on the extent of disease. A primary retrocardiac paraganglioma catecholamine-productive was identified in an asymptomatic 49-year old female associated to familial pheochromocytoma-paraganglioma syndrome caused by germline mutation of the gen which codifies for the subunit B of succinate dehydrogenase enzyme (SDHB). The neoplasm was surgically excised from the posterior surface of the left atrium via median sternotomy using cardiopulmonary bypass. Direct ligation of feeding vessels of the tumor along with left atrial reinforcement using a pericardial patch was performed. The post-operative course was uneventful, with normalization of catecholamine secretion and no recurrence at three-month follow-up. We review the current literature about this exceptional cardiac tumor, pathophysiological conditions and options for surgical management.

Prognostic impact of MGMT promoter methylation and MGMT and CD133 expression in colorectal adenocarcinoma.

BACKGROUND New biomarkers are needed for the prognosis of advanced colorectal cancer, which remains incurable by conventional treatments. O6-methylguanine DNA methyltransferase (MGMT) methylation and protein expression have been related to colorectal cancer treatment failure and tumor progression. Moreover, the presence in these tumors of cancer stem cells, which are characterized by CD133 expression, has been associated with chemoresistance, radioresistance, metastasis, and local recurrence. The objective of this study was to determine the prognostic value of CD133 and MGMT and their possible interaction in colorectal cancer patients. METHODS MGMT and CD133 expression was analyzed by immunohistochemistry in 123 paraffin-embedded colorectal adenocarcinoma samples, obtaining the percentage staining and intensity. MGMT promoter methylation status was obtained by using bisulfite modification and methylation-specific PCR (MSP). These values were correlated with clinical data, including overall survival (OS), disease-free survival (DFS), tumor stage, and differentiation grade. RESULTS Low MGMT expression intensity was significantly correlated with shorter OS and was a prognostic factor independently of treatment and histopathological variables. High percentage of CD133 expression was significantly correlated with shorter DFS but was not an independent factor. Patients with low-intensity MGMT expression and ≥50% CD133 expression had the poorest DFS and OS outcomes. CONCLUSIONS Our results support the hypothesis that MGMT expression may be an OS biomarker as useful as tumor stage or differentiation grade and that CD133 expression may be a predictive biomarker of DFS. Thus, MGMT and CD133 may both be useful for determining the prognosis of colorectal cancer patients and to identify those requiring more aggressive adjuvant therapies. Future studies will be necessary to determine its clinical utility.